Android 6.0 运行时权限处理问题

序

自从升级到Android M以来，最大的改变就是增加了运行时权限RuntimePermission，6.0以上的系统如果没有做适配，运行了targetSDK=23的App时就会报权限错误。我们知道6.0以下的系统是按照的时候权限申请的，6.0和之后的版本是我们想要使用某个app的权限，去动态申请的，这也是基于安全上的考虑吧（比如：单机的象棋对战，请求访问通讯录权限等不合理的权限，这肯定是有问题的）。

为了保护用户的隐私，谷歌官方将权限分为了两类，一个是正常权限（Normal Permissions），这类权限不涉及用户隐私，是不需要用户进行授权的，比如访问网络，手机震动等。还有一类是危险权限（Dangerous Permissions），一般是涉及到用户隐私的，需要用户进行授权，比如操作SD卡的写入，相机，录音等。

我们来看一张权限的清单文件：

我们可以通过adb shell pm list permissions -d -g进行查看。

权限如何申请

那么对于我们开发者来说，怎么适配6.0呢？按着官方的api走就行：

1,在AndroidManifest文件中添加需要的权限。

2,检查权限

if (ContextCompat.checkSelfPermission(thisActivity,
                Manifest.permission.READ_CONTACTS)
        != PackageManager.PERMISSION_GRANTED) {
}else{
    //
}

建议这些检查权限的代码可以写到基类里面去。

3,申请授权

 ActivityCompat.requestPermissions(thisActivity,
                new String[]{Manifest.permission.READ_CONTACTS},
                MY_PERMISSIONS_REQUEST_READ_CONTACTS);

说明：第一个参数是Context；第二个参数是需要申请的权限的字符串数组；第三个参数为requestCode，主要用于回调的时候检测。可以第二个参数看出，6.0是一次性申请多个权限的，系统会通过对话框逐一询问用户是否授权。

4，处理权限申请回调

@Override
public void onRequestPermissionsResult(int requestCode,
        String permissions[], int[] grantResults) {
    switch (requestCode) {
        case MY_PERMISSIONS_REQUEST_READ_CONTACTS: {
            // If request is cancelled, the result arrays are empty.
            if (grantResults.length > 0
                && grantResults[0] == PackageManager.PERMISSION_GRANTED) {

                // permission was granted, yay! Do the
                // contacts-related task you need to do.

            } else {

                // permission denied, boo! Disable the
                // functionality that depends on this permission.
            }
            return;
        }
    }
}

不过这里有个情况，对于用户上次拒绝的权限，在下次需要这个权限的时候，系统怎么处理的了？

if (ActivityCompat.shouldShowRequestPermissionRationale(thisActivity,
        Manifest.permission.READ_CONTACTS)) 
    // Show an expanation to the user *asynchronously* -- don't block
    // this thread waiting for the user's response! After the user
    // sees the explanation, try again to request the permission.

}

所以完整的处理逻辑：

if (ContextCompat.checkSelfPermission(thisActivity,
                Manifest.permission.READ_CONTACTS)
        != PackageManager.PERMISSION_GRANTED) {

    // Should we show an explanation?
    if (ActivityCompat.shouldShowRequestPermissionRationale(thisActivity,
            Manifest.permission.READ_CONTACTS)) {

        // Show an expanation to the user *asynchronously* -- don't block
        // this thread waiting for the user's response! After the user
        // sees the explanation, try again to request the permission.

    } else {

        // No explanation needed, we can request the permission.

        ActivityCompat.requestPermissions(thisActivity,
                new String[]{Manifest.permission.READ_CONTACTS},
                MY_PERMISSIONS_REQUEST_READ_CONTACTS);

        // MY_PERMISSIONS_REQUEST_READ_CONTACTS is an
        // app-defined int constant. The callback method gets the
        // result of the request.
    }
}

项目实践

权限工具类：

public class PermissionUtils {

    private static final ArrayMap<String, Integer> MIN_SDK_PERMISSIONS;

    static {
        MIN_SDK_PERMISSIONS = new ArrayMap<>(8);
        MIN_SDK_PERMISSIONS.put("com.android.voicemail.permission.ADD_VOICEMAIL", 14);
        MIN_SDK_PERMISSIONS.put("android.permission.BODY_SENSORS", 20);
        MIN_SDK_PERMISSIONS.put("android.permission.READ_CALL_LOG", 16);
        MIN_SDK_PERMISSIONS.put("android.permission.READ_EXTERNAL_STORAGE", 16);
        MIN_SDK_PERMISSIONS.put("android.permission.USE_SIP", 9);
        MIN_SDK_PERMISSIONS.put("android.permission.WRITE_CALL_LOG", 16);
        MIN_SDK_PERMISSIONS.put("android.permission.SYSTEM_ALERT_WINDOW", 23);
        MIN_SDK_PERMISSIONS.put("android.permission.WRITE_SETTINGS", 23);
    }

    private static volatile int targetSdkVersion = -1;

    public static boolean checkPermissions(int... grantResults) {
        if (grantResults.length == 0) {
            return false;
        }
        for (int result : grantResults) {
            if (result != PackageManager.PERMISSION_GRANTED) {
                return false;
            }
        }
        return true;
    }

    public static boolean hasSelfPermissions(Context context, String... permissions) {
        for (String permission : permissions) {
            if (permissionExists(permission) && !hasSelfPermission(context, permission)) {
                return false;
            }
        }
        return true;
    }

    private static boolean permissionExists(String permission) {
        Integer minVersion = MIN_SDK_PERMISSIONS.get(permission);
        return minVersion == null || Build.VERSION.SDK_INT >= minVersion;
    }


    private static boolean hasSelfPermission(Context context, String permission) {
        try {
            return PermissionChecker.checkSelfPermission(context, permission) == PackageManager.PERMISSION_GRANTED;
        } catch (RuntimeException t) {
            return false;
        }
    }

    public static boolean shouldShowRequestPermissionRationale(Activity activity, String... permissions) {
        for (String permission : permissions) {
            if (ActivityCompat.shouldShowRequestPermissionRationale(activity, permission)) {
                return true;
            }
        }
        return false;
    }

    @TargetApi(Build.VERSION_CODES.DONUT)
    public static int getTargetSdkVersion(Context context) {
        try {
            if (targetSdkVersion != -1) {
                return targetSdkVersion;
            }
            PackageInfo packageInfo = context.getPackageManager().getPackageInfo(context.getPackageName(), 0);
            targetSdkVersion = packageInfo.applicationInfo.targetSdkVersion;
        } catch (PackageManager.NameNotFoundException ignored) {
        }
        return targetSdkVersion;
    }
}

这里可以根据实际情况进行优化和扩展

基类：

public class BasePermissionActivity extends AppCompatActivity {

    private PermissionHandler mHandler=null;
    private static int requesrCode=001;

    /**
     * 请求权限
     */
    protected void requestPermission(String[] permissions, PermissionHandler handler) {
        if (PermissionUtils.hasSelfPermissions(this, permissions)) {
            handler.onGranted();
        } else {
            mHandler = handler;
            ActivityCompat.requestPermissions(this, permissions, requesrCode);
        }
    }


    protected void requestPermission( PermissionHandler handler,String permissions) {
        if (PermissionUtils.hasSelfPermissions(this, permissions)) {
            handler.onGranted();
        } else {
            mHandler = handler;
            ActivityCompat.requestPermissions(this, new String[]{permissions} , requesrCode);
        }
    }

    @Override
    public void onRequestPermissionsResult(int requestCode, @NonNull String[] permissions, @NonNull int[] grantResults) {
        super.onRequestPermissionsResult(requestCode, permissions, grantResults);
        if (mHandler == null) return;
        if (PermissionUtils.checkPermissions(grantResults)) {
            mHandler.onGranted();
        } else {
            if (!PermissionUtils.shouldShowRequestPermissionRationale(this, permissions)) {
                if (!mHandler.onNeverRequest()) {
                    Toast.makeText(this, "权限已被拒绝,请在设置-应用-权限中打开", Toast.LENGTH_SHORT).show();
                }

            } else {
                mHandler.onDenied();
            }
        }
    }


    public abstract class PermissionHandler {
        //权限通过
        public abstract void onGranted();

        //权限拒绝
        public void onDenied() {
        }

        //不再询问
        public boolean onNeverRequest() {
            return false;
        }
    }
}

测试：

public class MainActivity extends BasePermissionActivity {

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);

        init();
    }

    private void init() {
        request1();
    }

    private void request1() {
        requestPermission(new String[]{Manifest.permission.CAMERA}, new PermissionHandler() {
            @Override
            public void onGranted() {
                Intent intent = new Intent(); //调用照相机
                intent.setAction(MediaStore.ACTION_IMAGE_CAPTURE);
                startActivity(intent);
            }

            @Override
            public void onDenied() {
                Toast.makeText(MainActivity.this, "拒绝", Toast.LENGTH_SHORT).show();
            }
        });
    }


    private void request2() {
        requestPermission(new String[]{Manifest.permission.CAMERA}, new PermissionHandler() {
            @Override
            public void onGranted() {
                Intent intent = new Intent(); //调用照相机
                intent.setAction(MediaStore.ACTION_IMAGE_CAPTURE);
                startActivity(intent);
            }

            @Override
            public void onDenied() {
                Toast.makeText(MainActivity.this, "拒绝", Toast.LENGTH_SHORT).show();
            }
        });
    }
}

代码：https://github.com/xiangzhihong/permissionDemo

最后附上鸿洋封装的比较好的库：https://github.com/lovedise/PermissionGen